Apparatus for electrical separation of suspended material from gases



APPARATUS FOR ELECTRICAL SEPARATION OF SUSPENDED MATERIAL .FROM GASES Filed Sept. 11 1929 3 Sheets-Sheet 1 I N VEN TOR.

A TTORNEYS' June 16, 1931.

A. P. KNIGHT APPARATUS FOR ELECTRICAL SEPARATION OF SUSPENDED MATERIAL FROM GASES Filed Sept. 11 1929 3 Sheet s-Sheet 2 A TTORNEYS June 16, 1931. Q A, KMGHT 1,810,614

APPARATUS FOR ELECTRICAL SEPARATION OF SUSPENDED MATERIAL FRUM GASES Filed Sept. 11. 1929 3 Sheet-Sheet s IN VEN TOR /rf/Zz1r P MZZq/n .4 TTORNEYS AIYARATUS FOR ZQLECTRICAL SEPARATION OI! SIISPENDED MATRIAL FROM GASES Patented June 16, 1931 UNITED STATES PATENT orrlcr.

ARTHUR P. KNIGHT, OF GLENDALE, CALIFORNIA, ASSIGNOR T0 INTERNATIONAL PRECIPITATION COMPANY, 01 L08 ANGELES, C.ALIFORNIA, A CORPORATION OF CALIFORNIA Application filed September 11, 19 29. Serial No. 391,871.

This invention relates to an apparatus for electrical separation of suspende ma terial from gases and-the main object of the invention is to provide an electrical precipitating apparatus which will be of maximum effic1ency and capacity and of relatively low cost. A further object of the invention is to provide electrical precipating apparatus which will present maximum area of eflective collecting electrode surface in a given space and at the same time present certain advantages by reason of the special construction of the collecting electrodes as hereinafter set forth. I

It has been found desirable and advantageous in certain cases to use collecting electrodes of the so-called rod curtain type as disclosed in Patent No. 1,444,997, dated February 13, 1923, in which each collecting electrode consists of a multiplicity of rods or members spaced sufiiciently close together to produce substantially the effect of a continuous collecting surface as regards the effect on the electrical field, while at the same time providing certain advantages in the way of lightness, freedom from warpping under changes of temperatur and adaptability for jarring to remove collected material therefrom. The present invention is directed particularly to adapting this rod curtain construction 1n such manner as to provide maximum electrode surface in a given space. For this purpose I provide assemblages of rods arranged in rows, such rows intersecting so as to divide the precipitator space into compartments, discharge electrodes being provided in the respective compartments so formed.

.Meansare provided for conducting the gas to be treated in contact with the discharge and collecting electrodes and such means may provide for passing the gases longitudinally in the compartments parallel to the rods of which the collecting electrodes are composed or may provide for passing the gases transversely to said rodsas hereinafter explained.

The accompanying drawings illustrate embodiments of my invention and referring thereto:

-tator chamber through which the in Figs. 1 and 2, the precip'itator is shown as comprising a casing 1 forming a precipiases to be treated are passed, said casing being provided with aninlet opening 2 and an outlet opening 3. The inlet opening is connected to a flue 4 for supplying the gases to be treated and shown as below the precipitator chamber and the outlet opening above the precipitator chamber so as to rovide for upflo'w of gases through the preclpitator chamber, but it will be understood that this arrangement may be reversed so as to provide for downflow through the precipitator chambers. Horizontal bars or tubes 5 are mounted on fixed supports 6 above the precipitator chamber and within the casing 1 and a series .or row of collecting electrode rods 7 is mounted on each bar 5, said rods 7 being provided with heads 8 restin on members 5, (as shown in Figs. 4 and 5) the rods extending through holes in members 5 and extending also through holes in cross bars 9 extending across and within the casing 1 below the precipitator chamber. Y Transverse supporting members 10 formed as bars or tubes are shown as mounted ,on the bars or member 5, said members 10 being for example provided with flattened end portions 11 superimposed over the member 5 as shown in Fig. 5 and held in position by one oi the collecting electrode rods 7 passing through parts 11 and through the member 5. Members 12 similar to member 10 may be provided between the cross bars 9 below the precipitator chamber, bein mounted thereon in similar 'manner. number of rows or series of collecting electrode rods 7 are mounted on these transverse members 10 and 12, said members 7 being provided with heads 8 resting on the respective member 10. The described construction provides aseries of rows of collecting electrode rods which the transverse rows of electrodes are omitted. It will be understood that the rods or members 7 and 7' are spaced sufficiently close together so that their combined effect on the electrostatic fields within the precipitator chamber is substantially the same as that which would result from a continu-' ous metallic conductive surface so as to prevent these elements of the collecting elec trodes acting effectively as discharge electrodes. For this purpose as well as to increase the stiffness and stability of the collectin electrode construction, it is preferred to ma e the collecting electrode members 7 or 7 as rods, bars or tubes of, for example, from 4 inch to 1 inch diameter and in order to minimize the discharge effect from supporting bars 5,9, 10 and 12, these members are also preferably formed as rounded bars or tubes. In order that the rows of collecting electrode members shall produce substantially the effect of a continuous conductive surface as regards the distribution of the electrical field, it is necessary that these members he so closely spaced that a plurality of collecting electrode members is resented at each side of each compartment into which the precipitation chamber is subdivided as above described.

The discharge electrode system may be of any suitable construction consisting for example, of metallic wires, rods or chains 1f suspended from a frame 16 mounted on insulators 17 contained in insulator boxes 18 at the respective sides of the precipitator chamber, said discharge electrode wires being tensioned at their lower ends by weights 19 and spaced by a frame 20 hung on said Weights. Instead of wires any other suitable discharge electrode elements, such as rods or chains, may be used provided they present surfaces of suflicient convexity to insure the requisite amount of corona or silent discharge therefrom under the operating potential difference of the apparatus.

Means such as a bin or hopper 13, having a discharge gate 13 at its bottom, is provided below the precipitating chamber to receive and collect the material precipitated in the electrodes and falling therefrom in the operation of the apparatus.

The collecting electrode system may be grounded'in the usual manner as indicated at 21 and the discharge electrode. system above' described may be connected by an electrical connection indicated at 22 to any suitable source of high tension electrical current, for example, rectified alternating current, such as to maintain a unidirectional potential difference of say about 50,000 volts more or less and so as to maintain in the operation of the apparatus an electrical field between the discharge and collectin electrodes aforesaid of sufiicient intenslty to produce silent or corona dischar e from the discharge electrodes with a minimum of electrical discharge from the collecting electrodes.

Suitable dam er means 24 and 25 may be provided at the inlet and outlet of the precipitator casing as shown so as to control the flow of gas through the precipitator chamber, said damper means being controlled or operated by means indicated at 26 and 27 respectively.

Means are preferably provided for agitating or jarring the electrodes 7 and 7 so as to dislodge therefrom material deposited thereon by the action of the electrical field. For this purpose hammer means indicated at-3O may be mounted to swing on a shaft 31. carrying a pulley 32 operated by a chain or cable 33 so as to cause the hammer means to swing upwardly in either direction into contact with the bottom of the supporting beam 6 aforesaid in such manner as to imart a blow thereto sufiicient to jar the colecting electrode system.

J arring or agitating means may also be provided for the discharge electrode system consisting, for example, of hammer means 36 carried by a shaft 37 which also carries a pulley 38 adapted to be operated by a cable or chain 39 to cause said hammer means to swing down intocontact with an anvil 40 on the supporting frame 16 for the discharge electrodes. Normally the hammer means 36 is held in elevated position as shown in dotted lines in Fig. 1 so as not to interfere with the installation of the discharge electrode system and it will be understood that before said 'hammer means is brought into operation, suitable switching means, not shown, will be operated to disconnect the discharge electrode system from the source of supply and the hammer means 36 which is'mounted on the precipitator casing and is therefore, grounded, may then be operate to jar the discharge electrode system.

Distribution dampers 41 may be provided adjacent to inlet damper 24 to insure uniform distribution of the gas.

In the o eration of the apparatus above described tile gases are passed, for example,

upwardly through the precipitator chamber which is subdivided by the two transversely extending sets of rows of'discharge electrode elements into a multiplicity of vertically extending flues, the gas being subjected to the electrical fields maintained between each discharge electrode 15 and the collecting electrode members surrpunding such discharge electrode on all sides. T 1e described construction, therefore, produces substantially the efiect of a multiple pipe construction as regards the amount of collecting electrode area exposed while at the same time presenting the advantages of the rod curtain type precipitator. 01} of the advantages of this type of collec ng electrodes as compared with the construction in which the collecting electrodes consist of metal sheets or plates is that the collecting electrode elements 7 and 7 ar capable of independent vibration so that they may be jarred or vibrated much more readily and effectively than would be the case with a multiplicity of pipes rigidly connected together.

Instead of passin the gases to be treated vertically between t e discharge and collecting electrode means, such gases may be passed transversely to the discharge and collecting electrode means. For example, as shown in Fig. 3 the precipitator chamber, indicated at 42, may be provided with an inlet 43 and outlet 44 adapted to pass the gases horizontally through said chamber and the collecting electrodes 47 and 47 and discharge electrodes 45 may be hung vertically in said chamber in substantially the manner above described for the electrodes 7, 7' and 15 above described. In this form of the invention the collecting electrode elements may be mounted in two sets of rows of rods or tubes 47 and 47 extending transversely to one another in the same manner as above described and the discharge electrode means 45 may be mounted so as to extend respectively within the vertical compzrtments into which the precipitator chamr is subdivided by the transverse sets of collecting electrodes aforesaid, and the construction may be otherwise as above described, suitable means being provided, for example as above described, for jarring the electrodes for removal of the collected material and for supply of electrical high tension current to the electrodes. With the construction shown in Fi 3, the gas to be treated flows horizontally past the electrodes 47 and 47, the path of the gas stream being parallel to the rows of electrodes 47' and transverse to the rows of electrodes 47,

giving the general effect of a so-called,

plate-treater but with increased effective area due to presence of both sets of rows of electrodes.

The above described construction subside by side in contiguous relation andoc cupying the whole of said chamber, each such compartment being defined and surrounded by collecting electrode means comprising at each side of each such compartment a plurality of separate suspended vertical members capable of independent vibration but spaced sufiiciently close together to produce substantially the effect of a continuous surface as regards the electrical field.

I claim:

1. An electrical precipitator comprising a precipitating chamber, means for passing as to be treated through said chamber, colecting electrode means mounted in said chamber andcomprising two sets of rows of collecting electrode members, the rows of one set extending transversely to the rowsof the other set so as to subdivide the space within the precipitating chamber into a plurality of compartments, there being a plurality of collecting electrode members at each side of such compartment, and discharge electrode members mounted and insulated within said chamber and extending witiin the respective compartments aforesai 2. An electrical preci itator comprisin a casing forming a precipitator chamber an provided with inlet and outlet means for the gas to be treated, and with means below said chamber for collection of the recipitated material, a plurality of co lecting electrode members extendin vertically within said chamber and parallel to one another, a plurality of rows of collecting electrode members extending vertically within said chamber arallel to one another and transverse to t e first named rows of collecting electrode members so as to subdivide the precipitator chamber into a plurality of compartments, there being apluralit of collecting electrode members at each si e of such compartments, and discharge electrode members mounted within the said casing and extending in the spaces between the aforesaid transversely extending rows of collecting electrode members.

3. A construction as set forth in claim 2 and comprising, in addition, means for mounting said electrode 'members so as to be capable of independent vibration and means for jarring said collecting electrode members.

4. An electrical precipitator comprising a precipitator chamber, collecting electrode means mounted in said chamber andincluding suspended vertical members mounted in rows in such manner as to subdivide the precipitator chamber into a multiplicity of vertical compartments in contiguous relation, each compartment being defined and surrounded by a plurality of separate collecting electrode members spaced sufiiciently close together to produce substantiall the effect of a'continuous surface as regar the electrical field.

In testimony whereof I have hereunto subscribed my name this 3rd day'of September,

ARTHUR P. KNIGHT. 

